Add test harness for Parser.Error

parser-typechecker/tests/Unison/Test/FileParser.hs

@@ -3,9 +3,11 @@
 module Unison.Test.FileParser where
 
   import EasyTest
+  import Data.List (uncons)
+  import Data.Set (elems)
+  import qualified Text.Megaparsec.Error as MPE
   import Unison.FileParser (file)
-  import Unison.Parser
-  import qualified Unison.Parser as Parser
+  import qualified Unison.Parser as P
   import Unison.Parsers (unsafeGetRightFrom, unsafeReadAndParseFile')
   import qualified Unison.Reference as R
   import qualified Unison.Referent as Referent
@@ -13,6 +15,7 @@ module Unison.Test.FileParser where
   import Unison.UnisonFile (UnisonFile)
   import qualified Unison.Names as Names
   import Unison.Names (Names)
+  import Unison.Var (Var)
 
   test1 :: Test ()
   test1 = scope "fileparser.test1" . tests . map parses $
@@ -53,6 +56,18 @@ module Unison.Test.FileParser where
   test :: Test ()
   test = test1
 
+  expectFileParseFailure :: Var e => String -> (P.Error e -> Test ()) -> Test ()
+  expectFileParseFailure s expectation = scope s $ do
+    let result = P.run (P.rootFile file) s builtins
+    case result of
+      Right _ -> crash "Parser succeeded"
+      Left (MPE.FancyError _ sets) ->
+        case (fmap (fst) . uncons . elems) sets of
+          Just (MPE.ErrorCustom e) -> expectation e
+          Just _ -> crash "Error encountered was not custom"
+          Nothing -> crash "No error found"
+      Left _ -> crash "Parser failed with an error which was not fancy"
+
   builtins :: Names
   builtins = Names.fromTerms
     [ ("Pair"     , Referent.Con (R.Builtin "Pair") 0)
@@ -62,7 +77,7 @@ module Unison.Test.FileParser where
   parses :: String -> Test ()
   parses s = scope s $ do
     let
-      p :: UnisonFile Symbol Ann
+      p :: UnisonFile Symbol P.Ann
       !p = snd . unsafeGetRightFrom s $
-             Unison.Parser.run (Parser.rootFile file) s builtins
+             P.run (P.rootFile file) s builtins
     pure p >> ok